What distinguishes permissive joinder from mandatory joinder?

Permissive joinder allows parties to join together in a single action when their claims share a common question of law or fact, but it is not a requirement; the parties can choose whether or not to join. Conversely, mandatory joinder requires the presence of certain parties if their interests are so interconnected that a resolution of the case without them would be prejudicial. This distinction underscores that permissive joinder permits flexibility based on the parties' interests and the fit of their claims, while mandatory joinder emphasizes legal necessity to ensure all interested parties are present for a just resolution of disputes.

The other options mischaracterize the nature of these legal concepts. For instance, stating that permissive joinder is compulsory contradicts its nature as optional and relies on the willingness of parties to include claims that can be related. Similarly, the notion that permissive joinder applies only to defendants, while mandatory joinder applies only to plaintiffs, overlooks that both types of joinder can involve parties from either side of the litigation. Additionally, the statement regarding the requirement of a claim for permissive joinder misses the fundamental point that joinder even when optional still necessitates some claim being present to be joined; it does not eliminate the requirement for claims to exist. Thus